Prime Minister Nguyen Tan Dung has ordered four ministries to cooperate in identifying the causes of numerous vehicular fires that have plagued Vietnam since last year, VnExpress reported Saturday.

Under the PM's order, the Ministry of Transport will join hands with the Ministry of Public Security, the Ministry of Science and Technology and the Ministry of Industry and Trade to survey and study possible causes of the fires that have damaged or destroyed over 100 cars and motorbikes. Half of the cases remain unsolved.

The ministries were also ordered to inspect the quality of motorbikes sold at dealerships, and tighten the control over local bike maintenance and repair shops, according to the newswire.

Warnings against risks of fire and explosion as well as how to prevent them need to be issued by the transport ministry as well, it quoted the PM's order as saying.

In his emergency letter to the ministries, Dung also asked the ministries of technology and trade to review national standards for fuel, especially the contents of the additives currently alleged to have caused the fires.

The additives, including methanol, have allegedly been mixed with gasoline by fraudulent traders to earn profits. While helping increase the fuel's combustion, these additives can erode rubber materials, allowing fuel to leak and ignite.

Meanwhile, an investigation by Thanh Nien newspaper published this week exposed another fuel fraud, in which fuel trucks were found stopping at mysterious places along their way to gas stations to replace portions of their load with an unidentified liquid.

According to VnExpress, under the PM's order, the trade ministry will order its departments to inspect local fuel traders' operation. Any business found selling fuel that fails to meet regulated standards will have its license revoked, it said.

The transport of gasoline will also be put under scrutiny so that related agencies can not mix additives without permission, according to the report.

It quoted the order as saying that the Ministry of Public Security is responsible for inspecting and strictly punishing fraud committed in the trade and transport of fuel.

In related news, the taxi driver who was critically injured when his car caught fire in Ho Chi Minh City Wednesday succumbed to multiple burns and injuries Friday.

The fire broke out when Phan Duc Hoa, 32, was sleeping inside the car, which was parked in front of a gasoline station in District 12. Upon discovering the fire, locals tried to extinguish it and rescue Hoa, who was stuck inside.

Also on Friday, police in the southern province of Vinh Long said they are investigating the fire which engulfed a truck as it was traveling on the National Highway 1A. Locals managed to extinguish the fire, while the driver escaped without injuries, they said.